In many fields (e.g., medicine, manufacturing, veterinary science, scientific research, etc.), it is often necessary to examine a subject and communicate the results of the examination to a remote place. Such information exchanges are especially desirable in the medical arena where it is often useful for medical practitioners to communicate medical information, such as patient test results, to other practitioners located in remote places. Telemedicine facilitates this exchange of information.
Telemedicine is an emerging field that enables medical knowledge to be shared amongst a variety of users that need not be co-located. Interest in telemedicine has exploded in the 1990's with the development of medical devices for capturing data in digital electronic form and the establishment of high speed, high bandwidth telecommunication systems around the world. In particular, the use of the Internet in telemedicine allows a practitioner at one location to interpret medical test results and consult with another practitioner located elsewhere. Medical information transfer systems that employ the Internet allow for remote locations, such as third world countries that do not have an attending specialist, to access such medical expertise. Furthermore, emergency care may be provided where a practitioner is temporarily away, e.g., at home or on vacation. See, e.g., Thrall J H, Boland G., “Telemedicine in practice”, Seminars in Nuclear Medicine 28(2):145-57, April 1998.
Medical information (e.g., as may be utilized by a telemedicine system) may be derived from many different medical modalities. Such modalities may include sophisticated radiology equipment grouped as small matrix size and large matrix size instruments. Small matrix systems include equipment for magnetic resonance imaging (MRI), computed tomography (CT), ultrasonography (US), nuclear medicine (NM) and digital fluorography. Large matrix systems include equipment for computer radiography (CR) and digitized radiography (DR). Other data image acquisition equipment may be used for radiofluoroscopy, angiography, such as x-ray angiography and heart scanning. Still other equipment of great usefulness in acquiring medical information includes secondary capture devices for video, endoscopy, microscopy, and photography, such as digital cameras, scanners, electrocardiogram (ECG) machines, and the like.
The resulting medical information may take numerous forms, including text, images and video, or variations thereof, such as image overlay data, measurements, coordinates, etc. Information may also be in the form of time-dependent data including sound, such as audio dictation, and waveform data. The data may be static representations of time-dependent forms, such as curves. Thus, it is advantageous for telemedicine systems that may need to transfer the data and/or information to be flexible, so as to accommodate this variety of information/data from multiple modalities.
Unfortunately, this type of flexibility is not exhibited in current systems. For example, some current medical information transfer systems have integrated medical modalities to not only generate data but also to capture data signals, to store the data and to transmit the data over the Internet. Typically, in such systems the modality has an integrated Web server, storage database and Web pages as physical parts of the modality system. A remote Web browser is allowed to request data from the modality through the Internet (e.g., via the World Wide Web) and the Web server in the modality is allowed to respond accordingly. One such system, which has restricted applicability to ultrasound machines, is described in U.S. Pat. No. 5,715,823.
One drawback of such systems is that individual Web servers are required for each medical modality unit, making it a costly endeavor to share data among a number of practitioners. Furthermore, each server is limited in use to only the attached type of medical modality.
Other systems for transferring medical files are adapted to accept data from a variety of modalities, but require an interface to convert data into transferable signals. One such system described in WO 98/24358 converts system binary file data from a modality to a compatible file of keystroke codes using an adapter. The codes are transferred to a computer, which converts the codes to American Standard Code for Information Interchange (“ASCII”) characters for transmission over the Internet to a host computer. This multiple file conversion process is an unnecessary burden, however, as current Internet technology does not require that information be converted into ASCII format. Presently, the Internet accepts binary Extended Binary Coded Decimal Interchange Code (“EBCDIC”) and ASCII codes. Thus, an ASCII adapter is now an unnecessary extra device for transmitting medical data.
In addition to simply receiving the medical information, it is often important that a practitioner receive the information in a timely manner, especially where a quick diagnosis needs to be rendered for patient care. Thus, it is advantageous for telemedicine systems to rapidly transfer medical data. As noted, some current telemedicine systems rely on the Internet (i.e., as accessed through its graphically-oriented user interface, the World Wide Web) to transfer information. However, current Web-based transfer systems often suffer from long delays in downloading Web pages having complex data, such as large images. This presents a particular problem for the rapid sharing of medical information as a typical MRI study, for example, may have over 100 images, each of which may be 300 to 500 Kb in size, loading to a study of 50 to 80 Mb total.
These transfer times may be enhanced by compression of the data prior to transmission over the Internet. Traditional compression schemes (e.g., JPEG. GIF and bitmap schemes), however, tend to operate at low efficiencies. Such low compression efficiency may only provide for transfer of simple data before significant resolution losses and/or the truncation of data segments is/are experienced. With the use of high efficiency compression methodologies, such as wavelet compression techniques, transfer times can be reduced twenty fold. Unfortunately, however, the use of such high compression efficiency schemes is not prevalent among current telemedicine systems.
Another approach to solving the dilemma of lengthy transfer times is with the use of electronic mail (“e-mail”). E-mail provides a user with apparently instant transfer times, because information is sent as a package in advance. Using e-mail, studies may be “pushed” to the user so that the files are already available at the user's computer when the user is ready to view the data. By contrast, when a user requests a Web page through a browser, each page must be separately downloaded.
Some current e-mail technologies allow for the point-to-point transfer of a variety of data from different modalities. However, these systems do not operate with a central storage system. Without a server database, the operations are limited. For example, one may not retrieve information about how multiple images relate to one another. Such relationship information is essential for studying data from certain modalities, such as radiology images, and is required for compliance with some medical industry standards, e.g., the multi-specialty DICOM Standards (as originally published by an ACR-NEMA committee sponsored by the American College of Radiology and the National Electrical Manufacturers Association as Digital Imaging and Communications in Medicine (DICOM), NEMA Publications PS 3.1-PS3.12, by The National Electrical Manufacturers Association, Rosslyn, Va., 1992, 1993, 1994, 1995).
The DICOM Standards define the form and flow of electronic messages that convey images and related information between computers. Therefore, it is desirable for medical information transfer systems to acquire and transmit complex data, such as radiology images, in a manner that complies with DICOM standards. See, e.g., Bidgood, et al., “Understanding and Using DICOM, the Data Interchange Standard for Biomedical Imaging,” J. Am. Med. Informatics Assoc., 4:3, 199-212, May-June, 1997. As indicated, however, some systems do not meet this requirement.
Other medical e-mail systems are limited to purely textual data forms. An example of a medical information transfer system of this type is described in WO 98/16893. This system allows a service request to be sent by one operator through a client system to another operator at a sponsor system. The request may be for some action to be performed by the operator at the sponsor system, such as to perform a test, or to provide authorization therefor, and the like. Although perhaps useful, these textual systems are not designed to transfer complex data, such as images and multimedia output, generated by many medical modalities.
Thus, in light of the shortcomings of the various currently available systems, there is still a need for medical transfer systems that allow for transfer of complex data from a variety of modalities over e-mail and web browser systems.